A pictorial device which analyzes forces present on any body with the use of vectors. Allows easier grasping of problems involving either objects at equilibrium or in motion. Can be used to predict presence of forces.

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Confused about Newton's 3rd law

I am confused about Newton's 3rd Law. If a person jumps off the ground a force is applied both to the person and to the ground. However, as $F=ma$ acceleration experienced by the Earth is much less ...
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2answers
172 views

Tension of rope. Different Answers?

The tension of a rope in a tug of war with unequal forces is equal to the least force on the rope. Am I right? (If group A pulls the wire with 20 newton leftwards and the group B pulls with 30 newton. ...
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63 views

Work and Free Body Diagrams

I am a bit confused with how to find work when there is a free body diagram. I am trying to work out this problem, and in it a box is being pulled at a constant speed by a rope at a constant angle ...
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37 views

Find force of friction on an object under influence of tension by another object

I conducted an experiment using video analyses software, and found the accleration of a box on a table being pulled by a string attached to a pulley on the edge of the table attached to the weight ...
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118 views

What stops the car?

Centre of mass of a system cannot change its state of motion, unless there is an external force acting on it. Yet the internal force of brakes can bring a car to rest. Then what stops the car?
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140 views

Obtaining point of application of Ground Reaction Force with use of a hyperstatic load-cell array platform

I'm looking for the theory of an experiment that is giving me a hard time to perform. I have an instrument composed of a rigid horizontal square plate rigidly supported under each corner by a ...
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0answers
283 views

Free body diagram of stresses governing fracture propagation in a solid material

Reading this, I can intuitively understand that fractures propagate along the path of least resistance, creating "width in a direction that requires the least force". However, it is less intuitive ...
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7 views

Argument for stability of journal bearing via inertial and viscous forces?

As I understand a journal bearing, a rotor is levitated by hydraulic forces from the lubricant. While these are lots of studies on this subject, I can't manage to find a paper that coherently breaks ...
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67 views

Free body diagram of mechanisms

The image below shows a mechanism with 2 pin joints. On one of the pin joints, there is a torsional spring that exerts a torque $M_s = \kappa \theta$ (rest state is at $\theta = 0$). A force $F$ is ...
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251 views

Tension on a string pulled by unequal forces

Suppose two cases where masses are attached to massless, inextensible strings. In the first case a body which has a weight of 20 Newtons(downwards) is attached to a string which is acted upon ...
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73 views

Can't work out how the following free body diagram was created

I've been asked to draw a free body diagram of the following stepped bar setup: $ P = 10kN \;and\; Q = 30kN$ The one shown in the answer is the following: Could someone explain to me how this ...
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43 views

How would you explain the difference between these situations?

I have been thinking about this for quite a while, but I just can't seem to formulate a coherent answer. In problem which I will denote (a), we have a man sitting on some sort of chair and he is ...